Free written scope consultation - allowances, timeline, and change-order rules on paper before a single trade is scheduled
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AfterFast, Reliable Home Additions & ADU Across Addison
If you’re reading this, you’re likely weighing a room addition, a second story, or an ADU in Addison, TX. The short answer is this: a home addition in Addison typically runs $45,000-$130,000, while a detached ADU runs $90,000-$220,000, and a garage conversion lands between $30,000 and $80,000. The work almost always requires a structural engineer’s sign-off because of Addison’s clay soil, and you’ll want HOA approval in writing before any framing starts. We’ve been doing this work long enough to tell you exactly where the money goes and why.
Call us at (877) 610-1318 and we’ll walk you through what’s realistic for your property. No pressure, no vague estimates. Just numbers and a plan.
Why Barrett & Sons Construction Is Addison’s Preferred Home Additions & ADU Company
Tom Barrett founded this company in 1998, and his sons run the crews. When we say we know Addison, we mean we’ve pulled permits at Town Hall, sat through architectural review committee meetings in the Addison Circle district, and shored foundations on ProLogis-adjacent parcels off Belt Line Road. We’re not dispatching strangers from a call center. The name on the truck is the guy you’ll see at the hardware store on Midway Road.
Addison homeowners tell us the same story: a national outfit quoted one number, then handed them a change order for foundation work after demolition. We don’t work that way. Every scope item, every allowance, every price change comes to you as a written change order before any work happens. Tom’s cell number is on the contract. A live person answers 24/7, not a voicemail box in another state.
Our crews carry the Barrett & Sons name, which means background-checked and uniformed on every visit. If something’s not right inside 90 days, Tom comes back and makes it right. That’s the Done Right Promise, written on every contract.
Our Home Additions & ADU Services in Addison
Addison isn’t a town where you can just add a room on a half-acre lot. The 4.4 square miles are fully built out, which means nearly every Home Additions & ADU project we do in Addison involves working within an existing structure: a condo, a townhome, a late-90s Addison Circle building, or a mid-century apartment conversion. Here’s what that looks like on the ground.
Garage Conversion ADU
This is the most common ADU path in Addison, because there’s no empty land to build on. A garage conversion in Addison runs $30,000-$80,000, and the big variable is foundation. Many Addison garages sit on slabs poured directly over the Blackland Prairie clay, and if that slab has moved even half an inch, you need helical piers or slab repair before you can frame walls. We pull the permit, get the structural engineer’s approval, and coordinate the rough-in for plumbing and electrical with the Town of Addison’s inspection schedule. HOA rules in Addison Circle usually require the new exterior to match the original building’s materials exactly, so we source identical siding, brick, and roofline details before we submit plans.
New Detached ADU
A detached ADU in Addison is the rarest project we do here, and that’s precisely because of the zero-greenfield reality. You’re not building on a fresh lot; you’re building in a small side yard or behind an existing structure, often within a multifamily development’s setback rules. Plan on $90,000-$220,000, with the upper end driven by utility trenching through clay soil and a full foundation engineered for shrink-swell movement. If your HOA requires architectural committee approval, budget two to four extra weeks for review. We handle the drawings, the engineering, the permit pull, and the inspections so you’re not the one sitting in the meeting.
Junior ADU & Interior Conversion
A junior ADU (JADU) is the fastest way to add rentable or family space inside an existing Addison condo or townhome. Think converted den, finished basement, or a portion of the first floor with its own entrance, bath, and kitchenette. The cost usually falls within the garage-conversion range or lower. The catch in Addison: if you’re cutting into a load-bearing wall, even for a doorway, you need a structural engineer and a permit. Skip that step and you’ve voided the original builder’s warranty and left yourself with no third-party inspection of the rough-in. We’ve seen it happen. Don’t do it.
Second Story Additions
Going up instead of out makes sense in Addison, where there’s no out to go. A second-story addition typically starts around $130,000 and climbs, because the lower walls and foundation have to be reinforced to carry the new load. On Blackland Prairie clay, that usually means new footings, steel beams, and shoring during construction. We did a second-story addition in the Addison Circle district where the existing slab had shifted enough to throw a new beam out of level by nearly an inch. The fix was helical piers, a structural engineer’s sign-off, and a revised roofline that matched the new-urbanist design. The HOA approved it only after seeing the pier inspection report. That’s the kind of detail that keeps a project from sliding into six figures of surprise.
What happens when you call
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A real person answersNo phone trees - you reach a local pro.
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You get an upfront price rangeHonest numbers before anyone is dispatched.
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A background-checked tech heads outLicensed & insured, dispatched right away.
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You approve before work beginsNothing starts until you say go.
Trusted Brands We Service in Addison
When we frame windows and build out an addition in Addison, we use names you can look up: Simonton, Ply Gem, and PGT. These are brands with published specs and warranties you can verify. If a window in a new sunroom or second-story addition fails five years from now, the manufacturer stands behind it, and Tom Barrett’s phone still rings. For Addison customers, that matters, because our local supply runs mean faster turnaround on replacements and no mystery-brand materials off a van.
Common Home Additions & ADU Problems We See in Addison Homes
- Foundation movement on expansive clay. Addison sits on Blackland Prairie soils that shrink in 100°F+ Dallas summers and swell after rain. A room addition that meets code on day one can crack drywall and bind doors within two seasons if the slab wasn’t designed for that movement. We write the foundation scope like the soil is already moving, because it is.
- HOA architectural rules that stop work cold. Addison’s newer multifamily and Addison Circle buildings often require exact exterior material matching and setback preservation for ADUs. Starting an ADU without written HOA approval can trigger a stop-work order and permit revocation with the Town of Addison. We get approval before we ever pull a permit.
- Builder warranties quietly voided. Many Addison condo and townhome owners assume a small interior conversion for a junior ADU is cosmetic. It’s not. Opening a load-bearing wall without a structural engineer’s sign-off and a permit invalidates the original builder’s warranty. We pull the permit and get the engineer’s stamp every time.
- Unauthorized prior work hidden behind ceilings. Addison’s rapid turnover in multifamily buildings means previous owners sometimes did unpermitted work, like moving a wall or splicing electrical. We find it when we open the ceiling, and we fold the correction into a written change order before proceeding. You know the cost before we touch it.
Pricing for Home Additions & ADU in Addison, TX
Here are the honest ranges we quote for Addison’s market. These aren’t national averages; they reflect local permit fees, clay-soil engineering, and HOA compliance costs that add 10-18% over what you’d pay in a newer suburban subdivision with stable soil and no architectural committee.
| Project | Typical Addison Range |
|---|---|
| Home Addition | $45,000-$130,000 |
| ADU Construction | $90,000-$220,000 |
| Garage Conversion | $30,000-$80,000 |
What moves the number: foundation work on expansive clay, structural engineering for load-bearing walls or second stories, HOA-required material matching, and the cost of pulling permits and scheduling inspections with the Town of Addison. We price it all upfront. Call (877) 610-1318 for a free estimate and a written line-item scope. We also offer a Free Second Opinion on Any Written Estimate, so you can compare our numbers side by side with anyone else’s. And there’s a permanent 10% Senior & Veteran discount on every job.
We Also Serve Cities Near Addison
Our crews work throughout the Dallas-Fort Worth metro, including Addison and the surrounding communities. That means we’re in Carrollton, Farmers Branch, University Park, and Richardson regularly, so we know the permitting and HOA differences from one city to the next. If you’re just outside Addison, call us; the crew you meet will be the crew that shows up.
Serving Addison, TX - Our Local Coverage Area
We’re based in the Addison area and know this community well. Use the map below to see our service coverage - if you’re nearby, we can almost certainly help.
FAQs - Home Additions & ADU in Addison
They affect everything. Addison Circle’s architectural committee requires exact exterior material matching, setback preservation, and often a specific roofline profile before they’ll approve a garage conversion. Starting work without written HOA approval can trigger a stop-work order and permit revocation with the Town of Addison. We submit plans to the HOA first, get the approval in writing, then pull the building permit. Call (877) 610-1318 and we’ll tell you what your HOA specifically requires.
Because Addison’s Blackland Prairie clay shifts with seasonal moisture. A second story doubles the load on the lower walls and the slab, and if the slab has moved even an inch, the framing tolerances get thrown off. Neighboring suburbs with more stable soil may not need that engineering. Addison nearly always does. We budget for the engineer and the pier work upfront so there’s no surprise after demolition.
Only if the conversion doesn’t touch any load-bearing wall, and even then, you need to check the specific wording of your builder’s warranty. In Addison, many condo and townhome owners assume a small interior conversion is cosmetic. It isn’t. Cutting into a load-bearing wall without a structural engineer’s sign-off and a permit voids the original builder’s warranty and leaves no third-party inspection of the rough-in. We pull the permit and get the engineer’s stamp before any wall comes out. Call (877) 610-1318 to get a straight answer for your specific building.
Foundation work. On Addison’s clay, a room addition that meets code on day one can crack drywall and bind doors within two seasons if the slab wasn’t designed for shrink-swell. Most national quotes don’t include helical piers or slab repair; then the change order arrives after demolition. We write the foundation scope like the soil is already moving, so our $45,000-$130,000 range already accounts for the geotechnical reality. That’s why our written estimates tend to come in higher than a phone quote, and why our final bill matches the contract.
Check your HOA’s Covenants, Conditions, and Restrictions (CC&Rs) first, then call the Town of Addison’s building department for zoning and setback requirements. Most Addison apartment and condominium buildings require architectural committee approval before any ADU work. If you’d rather not sort through CC&Rs, call us at (877) 610-1318. We’ll look it up for you, with no charge to review your situation.
Get a Free Estimate for Your Addison Addition or ADU
If you live in Addison, TX, and you’re ready to talk about a room addition, second story, garage conversion, or ADU, call Barrett & Sons Construction at (877) 610-1318. You’ll get a live person, a straight answer, and a free estimate with every scope and allowance in writing. Tom Barrett’s name, address, and license number are published and verifiable. Ask anyone on your street, or look up the license yourself. We live twenty minutes away; if something’s wrong, we want to know about it.
Written by Tom Barrett, Owner at Barrett & Sons Construction, serving Addison and the Dallas-Fort Worth metro since 1998.